Master of Engineering (Research) / This thesis presents a new approach to ensuring fair service for highly concurrent requests. Our design uses the advantages of staged event-driven architecture (SEDA) to support high-concurrent loadings and makes use of control theory to manage the system performance. In order to guarantee the quality of service is fairly made to each request, based on SEDA, the control system for fairness is developed as a combination of a global control framework and a set of local self-tune stags. The global control framework is used to control the performance of the whole staged network at the top-level, aimed at coordinating the performance of the stages in the network. On the other hand, each self-tune stage under the control framework is built on the thread pool model, and will use automatic control theory to adjust its performance locally in order to meet the overall target performance. The automatic control system in each stage consists of an automatic modeling mechanism and a feedback module, which optimizes the controller parameters in the system automatically and guarantees the quality of performance (service rate here) for the stage at runtime. Based on mathematical proof and simulation results, our designs are implemented in a SEDA-based web server running in a dynamic loading environment. Results demonstrate that the performance of the new system in the real world is almost the same as the theoretical results. It demonstrates that the design is able to adaptively ensure the quality of service to the high-concurrent requests fairly. Compared to the original SEDA design, our design is an effective and handy approach to significantly enhancing the performance of SEDA in a variety of aspects, including fairer service, faster convergent speed, better robustness, higher accuracy and ease of deployment in various practical applications.
| Identifer | oai:union.ndltd.org:ADTP/216185 |
| Date | January 2007 |
| Creators | Zhanwen, Li |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
| Rights | The author retains copyright of this thesis., http://www.library.usyd.edu.au/copyright.html |
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